strptime: fix bug introduced in r272273.

Reported by:	portmgr (antoine)
Fix by:		Andrey Chernov, David Carlier
PR:		137307 (follow up)
Diff reduction with kernel code: instruct the compiler that the data of
these types may be unaligned to their "normal" alignment and exercise
caution when accessing them.

PR:		194071
MFC after:	3 days
Add IFCAP_HWSTATS.
Add an additional routing table lookup when m->m_pkthdr.fibnum is changed
at a PFIL hook in ip{,6}_output().  IPFW setfib rule did not perform
a routing table lookup when the destination address was not changed.

CR:	D805
Resurrect set_rcvar() as a function to define a rc.conf variable.
It defines a variable and its default value in load_rc_config() just after
rc.conf is loaded.  "rcvar" command shows the current and the default values.

This is an attempt to solve a problem that rc.d scripts from third-party
software do not have entries in /etc/defaults/rc.conf.  The fact that
load_rc_config() reads rc.conf only once and /etc/rc invokes the function
before running rc.d scripts made developers confused for a long time because
load_rc_config() just before run_rc_command() in each rc.d script overrides
variables only when the script is directly invoked, not from /etc/rc.

Variables defined in set_rcvar are always set in load_rc_config() after
loading rc.conf.  An rc.d script can now be written in a self-contained
manner regarding the related variables as follows:

---
name=foo
rcvar=foo_enable

set_rcvar foo_enable	YES	"Enable $name"
set_rcvar foo_flags	"-s"	"Flags to $name"

...

load_rc_config $name
run_rc_command "$@"
---
Do not strip outer header when operating in transport mode.
Instead requeue mbuf back to IPv4 protocol handler. If there is one extra IP-IP
encapsulation, it will be handled with tunneling interface. And thus proper
interface will be exposed into mbuf's rcvif. Also, tcpdump that listens on tunneling
interface will see packets in both directions.

Sponsored by:	Yandex LLC
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/aslr